A research program has been proposed to determine the feasibility of using Nl5-NMR resonance techniques, as a tool in the study of macromolecular phenomena, such as helix-coil transitions, hydrogen bonding, salt-bridging, and ionization of charged groups. Particular emphasis has been placed on comparing the relative sensitives of hydrogen, carbon-13, and nitrogen-15 nuclei to these phenomena. In order to increase the number of carbon-13 and nitrogen-15 nuclei in a protein, as well as to simplify the resulting NMR spectra, solid phase protein synthesis and biosynthesis techniques are being used to prepare specific site labelled ribonuclease S' and hemoglobin proteins. G-C MS techniques are simultaneously being developed for the N15 analysis of small quantities of amino acid and porphyrins.